I am no psychologist but I have interacted with paedophiles as part of my job remit and cunning and calculating is how I would describe every single one I have met.
This was a very interesting programme but it has already been shown-
DOCUMENTARY: To Catch a Paedophile
On: ITV1 Central (103)
Date: Tuesday 29th September 2009 (Already shown)
Time: 10:35 PM to 11:35 PM (1 hour long)
Second of two programmes in which child protection expert Mark Williams-Thomas follows officers in the Metropolitan Police's Paedophile Unit as they go undercover to catch predators targeting kids.
(Stereo, Part 2 of 2, Last In Series, Widescreen, Subtitles)
Basically a copper sits by a computer pretending to be a 13 year old girl on chat rooms and over weeks (or months) they eventually meet up where the paedo has a nasty surprise.
Virtually every one of them said "I came here to tell Becky that she shouldn't be doing this"
The American version is worth getting hold of which has been running for several years.